1.) No. Consider a case where you move a ball through air. Does it take the same energy it takes to move the same volume of air? No! The same way, the work to be done depends on it's mass and how far you want to move it.Work. But the force applied depends on the friction of the medium. Since viscosity of water is more than that of air, more force is needed. The viscous drag increases with velocity so more the speed, more force to apply. Ultimately the increased force means increased work to be done.

2.) work done=force applied*distance travelled. And the force applied includes the force you need to overcome the viscous drag.Work